Had the plugin developer look at the issue and they have resolved the problem. They asked to forward the solution to you:
found an issue with the plugin that your theme requires "Boutique Toolkit" which was using some WooCommerce code incorrectly and causing a conflict with the Memberships plugin. To fix that, I've edited the code and your site is now working properly :)
So that you can continue to use that "Boutique Toolkit" plugin in the future, could you send over this message to your theme's support? That way they can fix the issue so you can update the plugin in the future.
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Hello Boutique support,
There is an issue with boutique-toolkit/js_composer/shortcodes/blog.php on line 241:
$posts = new WP_Query( apply_filters( 'woocommerce_shortcode_products_query', $args, $atts ) );
The woocommerce_shortcode_products_query filter requires 3 parameters -- WooCommerce core made a mistake with this in 2.6 and it has since been fixed. Please update that filter usage to include a 3rd parameter, null works fine.
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